This invention relates to systems which employ water as a heat exchange medium so as to add heat to various parts of a building that are to be heated or to systems that employ water as a heat exchange medium to remove heat from various parts of a building to be cooled.
It is desirable that a system for heating various parts of a building be capable of responding to different demands for heating throughout the building at any time of the day or night. It is moreover desirable that such a system be capable of responding to reduced demands for heating during evening or nighttime hours when various parts of the building may not be occupied. It is also desirable that these same parts of the building be brought up to comfortable temperature levels during occupancy.
It is desirable that a system for cooling various parts of a building be capable of responding to different demands for cooling throughout the building at any time of the day or night. It is moreover desirable that such a system be capable of responding to reduced demands for cooling during evening or nighttime hours when various parts of the building may not be occupied. It is also desirable that these same parts of the building be brought down to comfortable temperature levels during occupancy.
This need to meet comfort levels during occupancy by either a heating system or a cooling system can present particular problems when water is used as the preferred heat exchange medium. In this regard, water in such a system usually needs to itself be first conditioned by appropriate equipment and thereafter circulated in advance of occupancy in order to meet the desired comfort levels during occupancy.
It is an object of the invention to provide a control for a system employing water as a heat exchange media which will accurately anticipate the needs of various parts of a building in advance of occupancy or at any other time of the day or night.
The present invention includes a controller for a system providing conditioned water to preferably a number of individual heat exchangers. The controller gathers information from local dedicated controllers associated with each of the heat exchangers. The gathered information includes information as to the current demand for conditioned water by each such heat exchanger as well information concerning the future demand for conditioned water.
The controller preferably creates an array of the thus received information by zone. The controller furthermore uses the received information that has been organized by zone to compute several additional pieces of information for each particular zone that is preferably stored in additional fields within the array. The additional pieces of information may include a start time for providing conditioned water to a particular zone.
The controller preferably first computes the percentage of dedicated local controllers currently having demands for conditioned water. The controller inquires as to whether the particularly computed percentage of dedicated local controllers is greater than a minimum demand requirement for conditioned water.
In the event that the particularly computed percentage of dedicated controllers is not greater than the respective minimum demand requirement for conditioned water, then the processor will proceed to an advance start routine. The advance start routine will determine whether or not there are anticipated demands in the future that might be combined with current demands so as to produce a future requirement for conditioned water that would be greater than the respective minimum requirement for conditioned water. The controller will proceed to determine the earliest start time that would produce a requirement for conditioned water that just exceeds the respective minimum requirement for conditioned water when anticipated demands in the future combined with current demands produce a future requirement for conditioned water that would be greater than the minimum requirement for conditioned water.
Following determination of the earliest start time, the system controller will set a system demand equal to heating if the system being controlled is a heating system. The system controller will set the system demand equal to cooling if the system being controlled is a cooling system.
The system will next check to see what the current mode of operation is before activating the heating system or the cooling system being controlled. If the current mode of operation is xe2x80x9cnonexe2x80x9d, then the system controller will proceed to actually authorize the start up of the particular system being controlled.